WOW - What is that? Through the years, that sort of exclamation has often been heard as groups explore the shallows of the outlet pond. One of the perennial favorites, the “pond poke” is a biological treasure hunt as we never know what we will bring up from the muddy bottom. Certain critters are pretty much guaranteed. Among them are the dragonfly and damselfly nymphs, tadpoles, scuds, water mites and back swimmers.

Each group of participants has a pond net used to scoop some mud and water which is then transferred into a white pan for easier viewing. A sampling of the organisms is put into a temporary aquarium where they can be observed by everyone before being released back into the pond at the end of the program. Hand lenses and microscopes help with close-up views of the smaller critters.

Scuds are tiny shrimp-like crustaceans that swim on their side, stroking with their legs. This explains their other name – sideswimmers. Water mites are tiny arachnids that often appear as miniscule red dots zooming about in the pan. Like the sideswimmer, the backswimmer’s name is descriptive, as it swims on its bell shaped back. Using its long legs like paddles to propel itself through the water. It is a true bug, with the piercing, sucking mouthparts of its kind and can inflict a painful bite. Knowing that from personal

experience I always warn against handling them. Dragonfly nymphs, however, can be handled with impunity. Easily ob- served, as they are relatively large, nymphs are a favorite of the pond poke. Like adult dragonflies, they are voracious preda- tors of mosquitoes and other insects. As adults they hunt on the fly, their legs folded like a basket to catch their prey. As nymphs, their hunting paraphernalia is perhaps the most bi- zarre of any in the pond. Their lower lip, or labium, is a long jointed structure with hooks at the end that is kept folded up when not in use. When a promising tidbit comes within range the labium shoots out, grabbing the prey with the terminal hooks. It is the nymphs that I have called little tigers in the pond. Dragonfly

Last year, however, they were eclipsed by a truly spec- tacular bug. I had only read about the Giant Water Bug in an account by a naturalist who was observing a frog when to his amazement its body deflated like a balloon when losing air. On investigating he realized it had been attacked by a Giant Water Bug. The largest of the true bugs, it grasps its prey with strong front legs. With its piercing mouthpart it injects a digestive enzyme that enables it to then suck out the liquefied insides of it’s prey. Gruesome from a human perspective, but effective. In July we caught one just half the size of the two large tadpoles in the aquarium. Even so I kept it isolated just in case. When the time came to release everything back into the pond, I made the mistake of thinking it would probably be safe to add the bug just for a minute so that everything could be viewed together. I regretted that decision in an instant, when the Water Bug not at all deterred by the much larger size of the tadpoles immediately grabbed one and killed it. Dragonfly nymph

In August a huge one was caught about three inches long and twice the size of the other. Or, it could have been the same one that had been eating really well. This time it was kept in total isolation throughout the program. With its large size and menacing front legs held like lethal pincers it was definitely the star of the show.

As always, it will be fascinating to see what makes an appearance at pond pokes this summer. Come join us throughout the season as we explore and celebrate the rich diver-